1. Field of the Invention
The present invention relates to a method of manufacturing a silica membrane, and more particularly to a method of manufacturing a silica membrane which has high separation performance and high permeation flux.
2. Description of Related Art
To separate a specific component from a mixed liquid containing a plurality of liquid components, a ceramic porous membrane made of a highly corrosive-resistant ceramic material, such as silica, alumina, cordierite, mullite, or silicon carbide, is used as a separation membrane (filter) for the dehydration from, for example, alcohol or an organic solvent.
The ceramic porous membrane is formed by depositing a ceramic sol onto a porous substrate, drying the ceramic sol, and then firing the same. The ceramic porous membrane is usually used integrally with the porous substrate, which serves as the support thereof.
As a method for depositing a silica sol, there has been known a method for forming a membrane by pouring a silica-sol liquid into a porous substrate by allowing the same to fall by its own weight (Patent Document 1). There has been known another method whereby a coating liquid prepared by diluting a ceramic sol concentrate solution by isopropyl alcohol is deposited and dried by air blowing (Patent Document 2).